Concentration of ores



Patented Mar. 24, 1931 UNITED STATES PATENT OFFICE RHETHERFORD B.MARTIN, F ROSELLE, NEW JERSEY CONCENTRATION OF ORES No Drawing.Application filed September'23, 1929. Serial No. 394,740.

This invention relates to improvements in should be carried on untilcomplete contact the concentration of ore, and more particuof themineral with the agents is obtained. larly to an improved method ofpreparing Water is then added to the material to form the ore forconcentration by flotation or a freely flowing pulp, which may hetreated water it th d by any method of froth flotation for the con- 55Heretofore the contacting of the selec- Centration of the mineral. tiveagents with the orc particles preliminary When-the mineral is to befinally sepato froth flotation or other concentration rated from thegangue by gravity water conmethods has been effected by mixing thecentration, the quantity and character of the agents with the ore in theform of a freely agents and the time of mixing should he so 60 fl ipulp, It i Common fl t tio ad usted that the mineral particles areagtice to apply the agents to the ore while glomerated. grinding to thefinal size in a ball mill. In VVhen treating an ore containing sulfideall these cases the Water present amounts to mlnerals, it is desirableto continue the mix- 35% to 350% of the weight of the ore. mg until thesulfides are agglomerated into 65 I have found that by regulating thewater shotlike granules which, by reason of their content of the ore toan amount just suflicient g eater gravity and bulk when compared to towet the surfaces of all the ore particles he Individual gangueparticles, may readily d i i th agents th ith b t m be separated bygravity water concentration,

bling in a revolving cylinder or equivalent It 1s desirable in this casethat'theore be 70 apparatus, the quantity of agents required is groundto at least pass a l8-mesh sieve. very much decreased. At the same time,I When treating a non-metallic ore, such as have obtained equal orbetter results in the a ph phate ore, the mixing should only besubsequent concentration than where the ornued o the point Where themineral di th d f t ti th agents ith particles are agglomerated intofloccules or 75 th or a acti d, featherhlie masses. Such floccules sinkless The amount of water required depends on rapidly In water than thegangue particles the degree of fineness to which the ore is n parationmay be readily made by ground .I have found that about 15% f gravityWater concentration. In this case w t b i ht i fli i t t tho hly the oreneed only be ground to such a degree 30 w t ll th surfaces f ti l id offineness that the mineral particles are subto pass a 6-mesh sieve, while20% to 25% stantially free from attached gangue parof water is requiredto thoroughly wet the holes. surfaces of ore particles ground to pass aThe following is an example of one method 48-mesh sieve. A preliminarytrial will inof carrying out this invention in the treatdicate theamountof water necessary for any n n f ph p Ore! particular ore. The quantityshould be suf- Q OQ grams of Florida phosphate ore ficient to thoroughlywet the surfaces of all screenmgs containing 55.8% bone phospha e theore particles without an excess which will of llme Was ground with 500cc. of water to e.

40 ttl t. f th ore on t di pass a 48-mesh sieve. The ore was then Whenthe mineral is to be finally separdeslimed by washing. The fine materialre-' ated from the gangue by the froth flotation moved amounted to 290grams and contained process, the ore should be ground to at least 63.9%'b ne phosphate of lime. The slime pass a 48-n1esh sieve, as is usual inflotation material is of sufliciently high grade to waroperations. Thecustomary selective agents rant further treatment for the recovery ofits may be employed, dependent-on the characphosphoric acid content. Thewater content ter of the ore. The quantity required, howof the deslimedmaterial was regulated by de ever, will be less than that usuallyrequired cantation to contain 20% of water by weight, for frothflotation operations. The mixing which was just enough water tothoroughly of thewetted ore with the selective agents wet all the oreparticles. Soluble soap at the rate of two pounds per ton and sodiumsilicate at the rate of one-half ound per ton were added to the wettedore. he ore, water, soap and silicate were then tumbled ina slowlyrotating cylinder for ten minutes, at the end of whichtime crudepetroleum oil was added at the rate of five pounds per ton of ore. Thetumbling was then continued for ten minutes. To the ore thus aglomerated, water was added to form a free y flowing pulp. The pulp wasthen fed to a small Wilfley concentrating table. The gangue material wasdischarged at what under the usual conditions of ore treatment is thecon centrate end of the table and the ag lomerate phosphate concentraterelatively ree from gangue was discharged at what under the usualconditions of ore treatment is the tailing side of the table. 1137 gramsof concentrate was produced, containing 73.4% bone phosphate of lime.The tailings weighed 385 grams and contained only .94% bone phos phateof lime.

The recovery of the bone phos hate of lime in the concentrate was 74.7%of t e phosphate in the original ore and 89.6% of the phosphate in theore actually subjected to agglomeration.

In another test, the ore was partially ground and deslimed. Water wasadded to the deslimed product to make the water content 40% by weight.The pulp so formed was ground in a ball mill, together with thefollowing agents in amounts per ton of ore:

' 8 pounds of soluble soap; 2 pounds of sodium silicate and 30 pounds ofcrude petroleum. Previous experiments had shown that these amounts werethe minimum for satisfactory results. The grinding and contacting periodwas 20. minutes. At the end of this time the ore was sufliciently fineto just pass a 48- mesh sieve and the phosphate minerals were wellagglomerated. The agglomerated ore was then fed to a small Wilfieconcentrating table as described above. phosphate and the grade of theconcentrate produced were sfbstantially the same as m the case wheretumbling the wetted or e wlth the agents out of the presence of agrinding medium was employed. It will be seen from this example that theuse of the known method of contacting ore with selective agents requiredfour times as much soap, four times as'much sodium silicate and sixtimes as much crude petroleum as that required when practicing themethod of this inventlon.

I claim: 1. In a process of ore concentratlon, the step of mixingthe-ore with selective agents which comprises re lating the water con--,tent of the ore to t e amount necessary to wetted ore with the seective agents.

e recovery of- 1,7e7,soo

2. In a process of ore' concentration, the steps which comprise grindingthe ore, adding water suflicient to thoroughly wet the surfaces of allthe ore particles without an excess which will settle out on standing,then tumbling the-wetted ore with selective agents until the mineralparticles have become thoroughlIy contacted therewith. v

3.. n a process of ore concentration, the steps which comprise grindingthe ore, adding water sufiicient to thoroughly wet the 4 surfaces of allthe ore particles without an excess which will settle out on standing,then tumbling the wetted ore with selective agents until the mineralparticles are agglomerated.

4. In a process of ore concentration, the steps which comprise grindingthe ore, adding water sufiicient thoroughly to wet the surfaces of allthe ore particles without excess which will settle out of the ore onstanding, and then mixing the wetted ore with a solu ble soap, an oiland an alkaline salt until the mineral particles are agglomerated intoflocculent bodies.

5. In a process of ore concentration, the steps which comprise grindingthe ore, adding water suificient thoroughly to wet the surfaces of allthe ore particles without an excess which will settle out of the ore onstanding, then tumbling the wetted ore with a soluble soap and analkaline salt followed by tumbling with a selective oil until themineralparticles are agglomerated into flocculent bodies.

In testimony whereof, I have signed my name to this specification this11th day of September 1929.

RIlETHERFORD B. MARTIN.

